Hello Yann,
especially Type 4 papers have b- values out of tolerance due to the high
amount of optical brighteners used by paper manufacturers in recent years.
This trend is still growing. A modification of ISO target values will
probably be done with a further revision (2006 ff). Today, users must
handle/communicate these high b- values in PT 4 papers accordingly.
A Fogra research work (2005, not published yet) the evaluation of twenty PT
4 paper shades found only two papers within ISO tolerance (b- value). See
data below.
Tab. 6: Farborte der Papiere des Papiertyps 4 (ungestrichen, weiß).
Papiernummer L* a* b*
Sollwerte 92 0 -3
Toleranzbereich 89 bis 95 -2 bis +2 -5 bis -1
1 93,3 2,5 -8,8
2 92,8 2,5 -9,2
3 93,2 1,6 -8,0
4 92,7 0,9 -6,0
5 93,2 1,8 -6,6
6 92,6 2,7 -9,9
7 93,1 1,7 -6,4
8 92,1 1,0 -6,2
9 92,4 1,0 -6,4
10 93,3 1,4 -7,9
11 93,1 1,4 -7,6
12 92,6 1,0 -6,2
13 93,2 1,1 -6,4
14 93,1 1,6 -6,3
15 93,2 1,6 -5,8
16 93,6 1,2 -7,2
17 91,6 1,4 -7,2
18 89,6 0,7 -3,0 *** 4/18 IGEPA Sopor Set 80 gsm
19 91,6 2,0 -7,1
20 92,8 1,0 -4,5 *** 4/20 SchneiderSöhne 625090 Planospeed ws 90 gsm
Freundliche Gruesse - Kind Regards
Karl Michael Meinecke
Bundesverband Druck und Medien e.V. (bvdm)
German Printing and Media Industries Federation (bvdm)
Biebricher Allee 79 | D-65187 Wiesbaden
Postfach 18 69 | D-65008 Wiesbaden
Fon +49(0)611 - 80 31 68 | Fax +49(0)611 - 80 32 68
mailto:km@bvdm-online.de | URL
www.bvdm.org
------------------------------------------------------
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-----Ursprüngliche Nachricht-----
Von: Yann Bouckaert [mailto:yannb@sagam.be]
Gesendet: Montag, 21. Februar 2005 20:56
An: eci-en(a)lists.transmedia.de
Betreff: [ECI-EN] ISO 12647-2 Paper Type 4: which?
Hello,
I am involved in bringing a sheetfed press to ISO 12647-2:2004 printing
standards for paper type 1, 2 and 4. Therefore, I measured all common
printing stock that this particular customer uses with a Gretag Spectrolino,
and ranked them according to the conformity of the Lab values for these
particular paper types. It was no problem finding paper fit for types 1 and
2, but every sample I took of his uncoated white stock was too blue. The b*
values were going from -6.4 to -7.2 (white backing).
My advice to him was to get some Zanders Zeta Matt white, because that was
used for the Altona tests.
Is there any other paper that qualifies?
Best wishes,
Yann Bouckaert
Sagam
Belgium
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